Server-side rendering with getServerSideProps

1. Introduction

In this tutorial, we're going to learn about server-side rendering with getServerSideProps in Next.js. We'll fetch data for each request and render a dynamic HTML page on the server side.

By the end of this tutorial, you'll have a clear understanding of server-side rendering and be able to implement getServerSideProps in your Next.js applications.

Prerequisites:
- Basic knowledge of JavaScript
- Basic understanding of React
- Familiarity with Next.js would be beneficial

2. Step-by-Step Guide

Server-side rendering (SSR) is the process of rendering web pages on a server and sending them to the client. Next.js provides a way to do server-side rendering with a function called getServerSideProps.

In Next.js, when you export a page component, you can also export an async function called getServerSideProps. This function will be called by the server on every request.

The function getServerSideProps should return an object like:

{ props: { /* your data here */ } }

This object will be passed to your page component as props.

3. Code Examples

Let's look at an example of how you can use getServerSideProps:

import fetch from 'node-fetch';

function Page({ data }) {
    // Render data...
}

export async function getServerSideProps(context) {
  const res = await fetch('https://api.example.com/data');
  const data = await res.json();

  if (!data) {
    return {
      notFound: true,
    }
  }

  return {
    props: { data }, // will be passed to the page component as props
  }
}

export default Page;

In this example, we're making a fetch request in the getServerSideProps function. The data fetched is then passed to the page component as props.

Note: The context parameter is an object containing various properties that you can use. For example, you can access query parameters with context.query, or the request and response objects with context.req and context.res, respectively.

4. Summary

We've learned about server-side rendering in Next.js and how to use the getServerSideProps function to fetch data on each request. With this knowledge, you can now render dynamic HTML pages on the server side.

For further learning, you might want to look into other data fetching methods in Next.js, such as getStaticProps and getInitialProps.

5. Practice Exercises

1. Create a simple Next.js app that fetches data from an API and displays it using server-side rendering.
2. Modify the app to fetch different data based on a query parameter.
3. Create an error handling mechanism for your server-side rendered app.

Tips for further practice:
- Use different APIs to fetch different types of data
- Experiment with handling various types of errors
- Try to combine server-side rendering with client-side rendering